Mexico union leader Elba Esther Gordillo in court
28 February 2013 Last updated at 07:44 GMT
Union head Elba Esther Gordillo, considered Mexico's most powerful woman, has been charged with the use of illicit funds and conspiracy.
Ms Gordillo, who runs the 1.5 million-member Mexican teachers' union, was arrested on Tuesday and is alleged to have embezzled more than $200m.
She reportedly spent millions on a US department store, plastic surgery, property and a private plane.
Her arrest came a day after the enactment of major educational reforms.
Will Grant reports from Mexico City.